Necrotic ring spot is a common disease of turf caused by soil borne fungi (Ophiosphaerella korrae) that mainly infects roots (4).

Necrotic Ring Spot is caused by a fungal pathogen that is an ascomycete that produces ascospores in an ascocarp (6).

Symptoms of the disease are quite noticeable since they appear as large yellow ring-shaped patches of dead turf.

Turf necrotic ring spot is known to infect various bluegrass and turfgrass species, especially the cool-season grasses.

They produce ascospores as a sexual reproductive structure in flask-shaped pseudothecia that are formed on roots and crowns of infected turf (6).

The pathogens survive unfavorable seasons as sclerotia, which are compacted mycelium that live in plant debris.

The pathogens are spread by grass trimming equipment such as a lawn mower as they carry the plant debris that contains the scelerotia (13).

Factors such as high soil pH and the correct level of moisture are critical for the development of this disease.

To summarize, the conditions that provide the most severity for this disease are environments of cooler temperatures, high dense thatch, a lower mowing height, and incorrect application and timing of fertilization (Nitrogen content too low) (11).

Cultural control includes the use of ammonium sulfate or other acidifying fertilizers to suppress the pathogen by lowering the pH of the soil to between 6.0 and 6.2.

In addition, reducing watering inputs and growing turf on well drained soils can lessen disease symptoms.

In a study where diluted pesticides were sprayed throughout infested test plots, Fenarimol was found to be the most effective with a 94.6% reduction of the disease.